Improvement in bakers  ovens



2 Sheets- Shet 1.

, the floor or bottom of the latter.

UNITED STATES PATENT DEEIQE DUNCAN MCKENZIE, on BROOKLYN, NEW YORK.

IMPROVEMENT IN BAKERS OVENS.

Specification forming part of Letters Patent No. 132,305, dated October15, 1872.

To all whom it may concern:

Be-it known that I, DUNCAN McKENzrE, of the city of Brooklyn, in thecounty of Kings and State of New York, have invented a new and usefulImprovement in Ovens and I do hereby declare that the following is afull, clear, and exact description of the same, reference being had tothe accompanying drawing forming part of this specification, and inwhich- Figures 1 and 2 represent sectional elevations, in planes atright angles to each other, of an oven constructed in accordance with myinvention, Fig. 1 being a section taken at the lines 00 a: in Figs. 2and 4, and Fig. 2 being a section at the irregular line y y in Fig. 4;

\ Fig.- 3 is a sectional elevation at the line z z in Fig. 4, whichlatter is a horizontal section at the line 10 w.

Similar letters of reference indicate corresponding parts.

This invention relates to baking-ovens in which the bread or othersubstance is baked by the direct contact of the. gaseous products ofcombustion from the fire or fires, and the same may be advantageouslyapplied to the oven constructed substantially as described.

in reissued Letters Patent, No. 3,929, dated April 19, 1870, grantedMary Ann Elizabeth McKenzie as assignee of myself, or to an ovenconstructed as shown in Letters Patent No. 115,626, issued to me June 6,1871, and in both of which a system of fines is used arranged tocommunicate between the fire-places and the interior of the oven,directly through The invention consists in a novel combination andarrangement of fines whereby, after the fire has been fairly lighted andthe draft is shut oft to prevent direct escape,the gaseous products ofcombustion, and steam or vapory matter eliminated from the substancebeing baked, are all returned from the oven back to the fire-place orash-pit thereof, thus keeping up the draft from the fire by a returnflue orfiues back to the fire and utilizing the gaseous products ofcombustion and vapors of the oven in a most perfect and economlcalmanner.

A represents the baking-chamber or oven,

heated by anysuitable number of fire-places B B, the gaseous products ofcombustion from which are passed by a system of passages or fiues, b cand d, in a direct manner through the bottom of the oven into andthrough the baking-chamber of the latter, from which the draft may becontinued through the top by an opening, 0, or otherwise, in a directmanner till the fires are fairly lighted, after which the opening a maybe closed by a damper, f. The fire-places B B are extended in rear oftheir grates g and ash-pits C. After the fires have been fairly lightedand damper f closed, the draft is kept up and the gaseous products ofcombustion, as also the steam or vapory matter eliminated from the breadin' baking, allowed to escape on opening-a damper, h, through one ormore passages, D, in the rear portion of the bottom of the oven, whichpassage or flue, that may be arranged between either pair of thefire-places, is in communication with a chamber, E, that connects byopenings 1' with the ash-pit O of the fire-places, thus returning thegaseous products of combustion, after they have done their duty in theoven, back to the fire; also directing the steam or vapory matter withinthe oven, after a proper retention therein, in the same direction, andestablishing a return draft through the ash-pits of the furnaces,whereby much economy of fuel is effected and a better baking of thebread or other substance within the oven obtained. F is a revolvingbreadcarrier, which may be constructed substantially as described ineither of the two Letters Patent hereinbefore referred to. I

lVhat is here claimed, and desired to be secured by Letters Patent, is'

The combination, with the baking-chamber A of the oven, and one or morefire-places, B, for heating the latter by the gaseous pro ducts ofcombustion entering said chamber, of a return fiue or flues D, arrangedto connect with the ash-pits O of the fire-places, substantially as andfor the purposes herein set forth.

,DUNOAN MCKENZIE. Witness-es: v

FE D. HAYNES, FEED. Tuson.

